What is the amplitude of $g(x)=10\cos\left(6x-1\right)-4$ ?
Amplitude in sinusoids of the form $f(x)=a\cos(bx+c)+d$ The amplitude of a sinusoid of the form $f(x)={a}\cos(bx + c) + d$ is equal to $|{a}|$. [How can we justify this given our graphical understanding of amplitude?] Finding the amplitude The amplitude of $g(x)={10}\cos\left(6x-1\right)-4$ is $|{10}|=10$.